Direct and Residual Effect of Organic Manure on Buckwheat ( Fagopyrum Esculentum Moench ) – Fodder Ricebean ( Vigna Umbellata ) Cropping System

The research programme was carried out during early summer seasons of 2012 and 2013 at the experimental farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar to study the direct and left over effect of organics on Buckwheat (Fagopyrum esculentum Moench) – fodder Rice bean (Vigna umbellata) cropping system. The trial was carried out in Randomized block design with 14 treatments and replicated thrice. Results demonstrate that combined application of vermicompost, poultry manures, mustard cake and farmyard manure improved seed yield of buck wheat by 0.51 and 0.53 t ha-1 over 100 % RDF in 2012 and 2013, respectively. Among the sole application of organic manures, application of poultry manure at 5 t ha-1 proved its superiority in terms of stem and seed yield of buck wheat. Collective application of vermicompost at 2.5 t ha-1 + mustard Cake at 2.5 t ha-1 + poultry manure at 2.5 t ha-1 + Farmyard manure at 4 t ha-1 to the preceding buckwheat crop produced 18.67 and 17.20% more fodder yield of ricebean than 100 % chemically treated plot during both the years. Application of vermicompost at 2.5 t ha-1 + mustard Cake at 2.5 t ha-1 + poultry manure at 2.5 t ha-1 + Farmyard manure at 4 t ha-1 also leave highest amount of available N, P and K in the soil. Economic analysis revelaed that treatment producing highest yield of buck wheat and ricebean fetched lower B: C ratio (0.63 and 0.74 during 2012 and 2013, respectively) as compared to other treatemnts. article history Received: 02 August 2017 Accepted: 11 February 2018

introduction Organic manures have traditionally been the important input as sources of plant nourishment.Organic manures directly provided macro and micronutrient and indirectly facilitates in improving the physical, chemical and biological properties of soils 1 .These manures, containing all the essential nutrients when applied to the preceding crop, leave the residual effect and this benefit is harvested by the succeeding crop to a great extent 2 .Organic matter is the heart of fertile soil.It helps in increasing cations and anions holding capacity of soil particularly phosphorus and nitrates.Throughout the crop growth period these adsorbed nutrient ions are slowly available for the benefit of crop.Use of organic matter plays a significant role in improving the use efficiency of applied nutrients and thereby reducing the expenditure of nutrient.Organic manuring has also been reported to improve the efficiency of nitrogenous fertilizers in acidic soils 3 .Buckwheat (Fagopyrum esculentum Moench) is a very old Asian crop, extensively grown throughout the globe.It is an important underutilized crop, plays a crucial role in meeting up the food security of the temperate and hilly regions of the countries in East Asia, East Europe and the himalayan region 4 .Though it is not a cereal, but the starchy seeds are generally classified among the cereal grains as of their similar usage.Ricebean (Vigna umbellata ) is a disease & insect resistant, fast growing legume crop and has the capability to produce huge amounts of healthy animal feed and high quality grain.Its cultivation is mainly confined to the Western, Northern and Eastern India and Nepal.It is broadly grown as an intercrop, predominantly of maize, and was traditionally being grown on residual moisture after rice.Ricebean can grow successfully in the large range of soils.Keeping the above facts in mind present experiment has been carried out to see the, direct and left over consequence of organics on the growth, yield and economics of buckwheatricebean cropping sequence.

Materials and Methods
This research trial was undertaken at the Research Farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India.The farm is located at 26 0 19'86" N latitude and 89 0 23'53" E longitude and at an elevation of 43 meters above mean sea level.The soil of the research plot was sandy loam in texture and acidic in nature having ph of 5.5.The initial organic carbon 0.639%, available nitrogen 107.59 kg ha -1 , available phosphorus 15.36 kg ha -1 and available potash 71.68 kg ha -1 were recorded before buck wheat cultivation in 2012.In the first year buck wheat variety VL-7 was sown during mid January with a row and plant distance of 30 cm X 7-10 cm.Fourteen treatments were allocated in randomized complete block design and replicated thrice.Treatments comprises of T 1 = Control (No manures/no fertilizers), T 2 = RDF (40:20:20), T 3 = Vermicompost @ 2.5 t ha -1 , T4 = Vermicompost at 5 t ha -1 , T 5 = Mustard Cake @ 2.5 t ha -1 , T 6 = Mustard Cake @5 t ha -1 , T 7 = Poultry Manure @ 2.5 t ha -1 , T 8 = Poultry Manure @ 5 t ha -1 , T9 = F.Y.M @ 8 t ha -1 , T 10 = RDF +FYM @ 4 t ha -1 , T 11 = Vermicompost @ 2.5 t ha -1 + Mustard Cake @ 2.5 t ha -1 , T 12 = Vermicompost @ 2.5 t ha -1 + Mustard Cake @ 5 t ha -1 , T 13 = Vermicompost @ 2.5 t ha -1 + F.Y.M @ 4 t ha -1 and T 14 = Vermicompost @ 2.5 t ha -1 + Mustard Cake @ 2.5 t ha -1 + Poultry Manure @ 2.5 t ha -1 + F.Y.M @ 4 t ha -1 .Nutrient concentration of vermicompost, mustard cake, poultry manure and FYM were N: P: K., 1.15:0.48:0.72,3.76:0.71:0.76,2.71:2.31:2.10 and 0.56:0.18:0.52 respectively.After the harvest of buck wheat, ricebean (variety: RBL-6) was sown as a sequence in the end of April on residual soil fertility without disturbing the original layout of main crop.Crop management practices for buck wheat and ricebean are similar during both the year.All the organics, (well decomposed) were incorporated on dry weight basis 20 days before sowing of buck wheat.20 days after application of organics as per treatment buck wheat were sown during 19 th January and 21 st January in 2012 and 2013, respectively with a seed rate of 40 kg ha -1 .Improved agro techniques were followed for the crops.All the plants from individual plots were harvested at physiological maturity and data on agronomic parameters were recorded.Composite soil sample from each plot were collected after harvesting of both buck wheat and ricebean.The samples were systematically dried up in shade, pulverized, passed through 0.2 mm net and then determined for the available N, P and K. Standard statistical methods were used for comparing the treatment means.Treatments variations were analysed on the basis of F test results and critical differences were calculated at 5% level of probability.Economics was calculated based on the prevailing market price.

Stem yield, Seed yield and harvest index of Buckwheat
The seed and stem yield of buckwheat was, in general more in 2013 than in 2012 irrespective of organic sources for nutrient management (Table 1).Significantly, the highest stem (2.83 t ha -1 during 2012 and 2.97 t ha -1 during 2013) and seed yield (1.65 t ha -1 during 2012 and 1.77 t ha -1 during 2013) was observed in integrated use of vermicompost at 2.5 t ha -1 + mustard cake at 2.5 t ha -1 + poultry manure at 2.5 t ha -1 + F.Y.M at 4 t ha -1 (T 14 ) might be due to more leaf area, dry matter accumulation, crop growth and yield attributes followed by joint application of vermicompost at 2.5 t ha-1 + mustard cake at 5 t ha -1 (T 12 ) that was statistically equal with sole appliance of poultry manure at 5 t ha -1 (T 8 ) during both the years of experimentation.The improvement of buckwheat yield due to different organic sources of nutrients could be attributed to the by and large advancement of crop growth, production and translocation of sufficient photosynthate.Unfertilized control (T 1 ) recorded the lowest stem and seed yield of buck wheat during both the years of investigation.The results confirmed the experimental findings of Dietrych et al., 5,6 .+ mustard cake at 2.5 t ha -1 + poultry manure at 2.5 t ha -1 + F.Y.M at 4 t ha -1 followed by joint use of vermicompost at 2.5 t ha -1 + mustard cake at 5 t ha -1 (34.1 % during 2012 and 35.2 % during 2013) which was statistically equal with sole appliance of poultry manure at 5 t ha -1 (33.3 % and 34.9 % during 2012 and 2013, respectively).Unfertilized control (T 1 ) recorded significantly the lowest harvest index of 23.3 % and 25.3 % during 2012 and 2013, respectively.

growth attributes and Fodder yield of Rice Bean
Combine application of poultry manures, mustard cake vermicompost and FYM to previous buckwheat crop significantly increased fodder yield of rice bean by 4.0 and 4.5 t ha -1 , during 2012 and 2013, respectively, over 100 % RDF (Table 2) might be due to higher residual fertility for greater nutrient uptake and availability.Similar significant increases on plant height (115.6 and 117.8 cm), number of branches plant -1 (5.2 and 5.3) and number of leaves plant -1 (77.7 and 78.3) were also observed in T 14 followed by joint use of vermicompost at 2.5 t ha -1 + mustard cake at 5 t ha -1 (T 12 ) which was statistically equal with the sole application of poultry manure at 5 t ha -1 (T 8 ) during both the years of experimentation.As soil of terai region is sandy loam with light textured, prevailing with high rainfall, causes leaching down of nutrients, that's why combined application of all the organic manures was added in treatment T 14 .All the treatments comprised organic sources of plant nutrient exhibited positive left over consequence in terms of yield traits and fodder yield of rice bean than chemically treated and control plot.Chemically treated plot left insufficient amount of nutrient for the succeeding crop as most of the nutrients was utilized by the preceding crop and some portion was lost from the soil as compared to organically amended plots, as a result performance of rice bean was not at par with the organically amended plots.These results are in accordance with the findings of Iqbal et.al., 7,8,9 .

Soil nutrient Status
Results showed that available nutrient content of soil depleted after completion of crop sequence as compared to their initial level (before buckwheat).Collective application of vermicompost at 2.5 t ha -1 + mustard cake at 2.5 t ha -1 + poultry manure at 2.5 t ha -1 + F.Y.M at 4 t ha -1 (T 14 ) witnessed considerably highest values of available nitrogen (161.9 and 168.2 kg ha -1 ), phosphorus (26.2 and 34.3 kg ha -1 ) and potassium (124.0 and 127.5 kg ha -1 ) followed by vermicompost at 2.5 t ha -1 + mustard cake at 5 t ha -1 and mustard cake at 5 t ha -1 during both years of experimentation.Organically treated plots recorded higher values of available nitrogen, phosphorus and potassium than chemically treated plots during both the years of experimentation.The probable reason might be due to losses of nutrients from chemically treated plot.The available nitrogen was higher might be due to the fixation of atmospheric nitrogen by buckwheat.It was also found that whenever, poultry manure was applied either solely or combindly with other organic manures recorded maximum available potassium in both the years, it might be due to higher potassium content in poultry manure.The result of the present study is in agreement with the result of Singh et.al., 8,9,10 .

Economics of Buckwheat-Rice Bean Sequence
The data on economics of buckwheat-ricebean cropping sequence in relation to organic manures and chemical fertilizers have been presented in Table 3 and 4. The economics analysis revealed that maximum gross return of ₹ 91500 and ₹ 97920 ha -1 were achieved with collective application of vermicompost at 2.5 t ha -1 + mustard cake at 2.5 t ha -1 + poultry manure at 2.5 t ha -1 + F.Y.M at 4 t ha -1 i.e.T 14 closely followed by ₹81820 and ₹88300 ha -1 with vermicompost at 2.5 t ha -1 + mustard cake at 5 t ha -1 i.e.T 12 during 2012 and 2013, respectively.higher gross return was simply due to higher yield of both the crop in the sequence during both the years of experimentation.The results showed that all the organic treatments recorded higher gross returns as compared to chemically treated and control plots.Among all treatments T 8 (poultry manure at 5t ha -1 ) registered the highest earnings to the tune of ₹51901 ha -1 in 2012 and ₹57941 ha -1 in 2013.This was next to T 2 (₹44992 ha -1 in 2012 and ₹50351 ha -1 in 2013).The net returns were less in first year of experiment as compared to the second year simply due to lesser yield for buckwheat and ricebean in the first year.Among the organic manures mustard cake recoded comparatively lower net returns in both the years might be due to higher unit price (₹ 8.0 kg -1 ) of mustard cake.The highest benefit: cost ratio (2.33 and 2.59 during 2012 and 2013, respectively) was noticed in T 2 (100 % RDF) followed by T 10 (2.07 and 2.33 during 2012 and 2013, respectively).This was owing to the less cost incurred by these treatments.The results corroborate with the earlier findings of Panwar and Munda 11

table : 3 impact of organic sources of nutrients on soil fertility after harvesting of rice bean
and Jat et.al.,12 .

table : 4 Cost of production of buckwheat and ricebean as influenced by organic sources of nutrients treatments cost general cost for
Input cost of urea, single super phosphate, muriate of potash, farm yard manure, vermicompost, poultry manure and mustard cake were ₹6,8,15,1,4,2 and 8kg -1 respectively. table:

4 Economics of buckwheat-ricebean sequence as influenced by organic sources of nutrients treatments Return from Return from gross return net return Benefit: Cost buckwheat rice bean (₹ ha -1 ) (₹ ha -1 ) ratio ( ₹ ha -1 ) (₹ ha -1 )
Selling price of buck wheat and faba bean were ₹70 and 40 kg -1 , respectively.